1. Technical Field
The present invention relates generally to power tools and more particularly to the construction of a housing for a power tool and a method for assembling a power tool.
2. Discussion
A common problem with power tools, particularly portable power tools of the pistol-grip or midhandle configuration having a xe2x80x9cclam-shellxe2x80x9d construction, concerns the region of the housing where the handle portion intersects the motor/geartrain portion that houses the motor and geartrain assemblies. Due to ergonomic concerns, the handle portion is typically narrower than the motor/geartrain portion to permit an operator to handle and manipulate the power tool in a comfortable manner. Considerations for the overall appearance of the power tool frequently prevent the intersection between the handle portion and the motor/geartrain portion from being strengthened sufficiently to prevent these portions from moving relative to one another when a force is applied to the housing, as when the power tool is dropped. Another drawback of the xe2x80x9cclam shellxe2x80x9d construction concerns the ability with which a power tool so constructed may be assembled. Typically, power tools having a xe2x80x9cclam shellxe2x80x9d construction are assembled in a process wherein the sub-components which form the tool are initially installed to a first clam shell half and thereafter a second clam shell half is coupled to the first clam shell half, securing the sub-components between the clam shell halves.
An often tedious and time-consuming operation in this process concerns the engagement an output member of a motor assembly with an input member of a geartrain assembly. Often it is necessary to move the motor assembly and geartrain relative to one another to engage the output and input members. Unfortunately, as the sub-components of the power tool are usually not fixedly secured to the first clam shell half, movement of the motor assembly and/or geartrain assembly frequently causes one or more sub-components to dislodge from the first clam shell half, thereby increasing the risk that a defective power tool will be produced.
It is therefore one object of the present invention to provide a power tool having improved resistance to breakage at an intersection between a handle portion and a motor/geartrain portion.
It is another object of the present invention to provide a power tool having a construction which moderates the difficulty with which a motor assembly and a geartrain assembly are meshingly engaged.
A power tool overcoming the above-mentioned drawbacks is provided herein. The power tool includes a first housing assembly, an attachment post and a second housing assembly. The first housing assembly includes a motor assembly and a first wall member. The first wall member defines a first cavity having a longitudinal axis and terminates at a first abutting face. The attachment post has a longitudinal axis and is coupled to the first housing assembly such that the longitudinal axis of the attachment post is perpendicular to the longitudinal axis of the first cavity. The second housing assembly is coupled to the first housing assembly and includes a geartrain assembly, a second wall member and an attachment hook. The second wall member defines a second cavity which terminates at a second abutting face. The attachment hook has a slotted aperture with a longitudinal axis and first and second sidewalls. The longitudinal axis of the slotted aperture is parallel to the longitudinal axis of the second cavity and the first and second sidewalls of the attachment hook slidably engaging the attachment post. The attachment hook and attachment post strengthen the power tool and are employed to align the first and second housing assemblies to one another, thus moderating the difficulty with which the motor assembly and the geartrain assembly are meshingly engaged with one another. Accordingly, a method for assembling a power tool is also provided.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings.